US2925461A

US2925461A - Electric wire connector

Info

Publication number: US2925461A
Application number: US388969A
Authority: US
Inventors: Anderson John Wiley
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-10-29
Filing date: 1953-10-29
Publication date: 1960-02-16
Anticipated expiration: 1977-02-16

Description

Feb. 16, 1960 J. W. ANDERSON ELECTRIC WIRE CONNECTOR Filed Oct. 29, 1953 ATTORNEY United States Patent ELECTRIC WIRE CONNECTOR John Wiley Anderson, Newtown, Conn.

Application October 29, 1953, Serial No. 388,969

Claims. (Cl. 174-87) This invention relates to a compound connector for holding bound together in electrical contact and thoroughly insulated from surroundings the bared free ends of a plurality of electrical conductors.

In former practices of joining together free bared ends of insulated electric conductors, as within an outlet or junction box, it has been proposed in place of the old fashioned method of soldering the wire ends together and then covering them with a winding of insulative tape to bind the free wire ends together in side by side relation with their ends flush by screwing thereon a cap nut, the same being a thimble type of connector usually comprising a thick walled insulative cup internally lined with metallic screw threads. Satisfactory fastening together of electric wires by such means and without soldering necessitates a nice fit of the overall girth of the combined Wire ends with the internal screw threaded hole in the connector. This necessitates having at hand a variety of sizes of connectors so that a size can be chosen that properly fits the quantity and sizes of wires to be joined thereby.

Given a proper fit between the combined wires and a cap nut type of connector the latter when screwed onto the former must indent or cutv its own thread in the bared surfaces of the Wires. If the wires are of copper or other soft metal, and particularly if of the stranded type, the screwing on of the connector Will tend to twist and sever individual fine strands of the wire.

it is an object of this invention to provide connectors of uniform size that will bind quickly and firmly together and insulate dependably from their surroundings the bared free end portions of a gang of insulated wires that may vary in number, kind and size and without danger of breakage or impairment of the wires even if of the stranded type.

A contributary object is to provide a connector that comprises an easily applied insulative sheath made of separate parts that can be coupled together more quickly than by screwing a cap nut directly onto the wires as aforesaid and that demands less finger strength of the user.

A further object is to relieve the insulative parts of the connector, especially if made of molded plastic material, from the forceful stresses and strains that need be exerted for holding the wires mechanically bound together.

A still further object is to make the insulative sheath of individual parts that are easily separable after assemblage and reusable.

The foregoing and related advantages of the invention will appear in greater detail from the following description of successful embodiments of the present improvements having reference to the accompanying drawings wherein:

Fig. 1 shows in larger scale than ordinary size an assemblage of wire terminals and one form of compound connector embodying the invention viewed partially in section on the plane 1-1 in Fig. 2.

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Fig. 2 is a plan view of the assembled insulative parts of Fig. 1, the conductors and their metallic binder being omitted.

Fig. 3 shows partially in central section the boot part of the insulative sheath detached.

Fig. 4 shows partially in central section the retaining collar of the insulative sheath detached.

Fig. 5 shows the mechanically bound together electrical conductors of Fig. 1 housed within a modified form of insulative sheath viewed in section on the plane 5-5 in Fig. 6.

Fig. 6 is a plan View of the assembled insulative parts in Fig. 5, the conductors and their metallic binder being omitted.

Fig. 7 shows partially in central section the boot part of the insulative sheath of Fig. 5 detached.

Fig. 8 shows partially in central section the retaining collar of the insulative sheath of Fig. 5 detached.

Fig. 9 shows the mechanically bound together electrical conductors housed within an insulative sheath of still differently modified construction viewed in section on the plane 99 in Fig. 10.

Fig. 10 is a plan view of the insulative parts in Fig. 9, the bound conductors and their metallic binder being omitted.

Fig. 11 shows partially in central section the boot part of the insulative sheath of Fig. 9 detached.

Fig. 12 shows partially in central section the retaining collar of the insulative sheath of Fig. 9 detached.

Fig. 13 is a fragmentary view of a portion of Fig. l drawn on a larger scale and shows the barbed locking prongs of the boot in partially and in fully inserted positions during coupling assembly of the boot with the retaining collar.

in Figs. 1 to 4, inclusive, three insulated electrical conductors 12 have side-by-side bared free wire ends 13 locked in electrical contact with one another by the wire squeezing indentations at 14 in the tubular wall 15 of an open ended metallic binder or splicer sleeve 16 that sleeves over the combined wire ends 13 and has an outwardly extended rim portion at its open end. The extreme terminals 17 of the bared wire'ends may or need not project from the other or smaller open end of the binder 16. I

The nature of the mechanical hold of the binder upon the wire ends produced by indenting the metallic tubular walls 15 so that any contained wires are held tightly squeezed together therewithin is such that a considerable variety of numbers, kinds and sizes of wire can thus be held together by the use of a uniform size of binder. Also the mechanical holding together of the Wires by means of such binder does not inflict any stress or strain on plastic housing parts of brittle or deformable nature such as constitute the two-piece insulating sheath next to be described.

This sheath comprises a boot 21 of a strong, tough and somewhat resilient plastic material such as molded nylon whose structure is clearly shown in the detached view thereof in Fig. 3. Boot 21 has a relatively small closed end 20 and a relatively large open end 22 which latter is castellated to afford three fastening prongs 23 having barbed terminals 24 and capable of flexing between full line and broken line positions in Fig. 3 when the open end of the boot is slightly deformed out of round by squeezing it inwardly within the elastic limit of the material. Such inward squeezing is permitted by the resilience of the relatively thin wall of the boot in the region of its open end.

Fig. 4' shows another part of the two-piece insulative sheath that comprises a cup-shaped retaining collar member 26 which like the boot 21 may be of nylon. Collar 26 has three eccentrically located apertures 27 through fied retaining collar 38. 'the 37 aperture is narrower in a radial direction than the tubular core wall 30 of collar 26 in Fig. 1.

boot 21. The apertures 27 are so spaced at such radial distance from the center of the collar thatin order to enter such apertures the prongs 23'by camming action will be forced to spring inward from their full line to their broken line positions in Fig. 3 or from their brokenline position to their full-line position in Fig. 13 until the locking barbs 24 clear the top ends of the apertures 27. Then the prongs automatically snap radially outward in ang'ularly divergent planes into positive clinging and interlocking relation to the collar 26 as shown by full lines in Fig. 1 and by broken lines in Fig. 13. To

further act as a reliable stay for the barbs in this interlocking position they are caused to seat in an annular beveled groove 25 in the collar 26.

In Fig. 1 the locked together relation of'the boot 21.

and retaining collar 26 is shown to imprison the binder 16 within the boot, the flared open end of binder 16 projecting into the annular channel 29 in the base 28 of retaining collar 26 so that a short length of the thin tubular core wall or hollow lug 30 of the collar that borders channel 29 intervenes between the outward extended rim of the binder 16 and the insulated con ductors 12 and alfords a stop lug operative to prevent withdrawal of binder 16 from the boot when the boot and the collar are locked together by prongs 23.

By springing the barbed prongs 23 inwardly, as is permitted by the excess space in apertures 27, the two parts of the sheath may be separated and reused, or either of boot 21 and retaining collar 26 may be replaced by some corresponding part having equivalent locking form an angular return bend. The angle formed by the free branch of the hook can spring toward the stem 34 of the prong within the elastic limit of the nylon material, or other resilient plastic material, of which the boot is made thus to enable the hooked end of the prong to be forced through its aperture 37 in the modi- In this form of the invention is the normal unsprung overall width of the hooked end of the prong in a radial direction.

The modified form. of cup-shaped retaining collar member 38 in Fig. 8 has a thin walled hollow lug or horn 39 projecting from the cross wall thereof which in the assembled relation of the parts in Fig. 5 is seen to intervene between the insulated conductors 12 and the flared end of the binder 16 in a manner similar to In operation the two part sheath of Fig. 5 can be assembled by merely forcing the boot and the collar toward each other in axial direction. This will cause the hooked end of the prong to cam its way through the aperture and then automatically spread with a snap into the'collar engaging position shown in Fig. 5. The parts thereafter can be separated by squeezing the hooked end 35 toward the stem of the prong 34' so as to decrease the normal angle therebetween sutficiently to enable the prong to pass through aperture 37 in a separating direction.

Both of the forms of construction shown in Figs. 1 to 8 involve a retaining collar that must be slipped over the insulated conductors before the boot is applied. Figs. 9 to 12, inclusive, show a still further modified form of construction of the two part sheath'wherein the retaining collar 41 can be applied to the boot 42 afterthe latter has been placed in covering relation to the binder 16.

In Figs. 9 and 12 collar 41 is seen to be provided with a series of conical counterbores 43 which produce step-like shoulders 44 therebetween internally of the collar. Both the maximum and minimum diameters of the bores 43 at the shoulders 44 are of smaller girth than the normal unsprung overall spread of boot arms or prongs 45. These arms normally assume their relatively flaring relation shown in Fig. 11 being separated by three V-shaped notches to form the castellated open end of boot 42. At the base of arms 45 internally of the boot there is an annular head 46 that reduces the girth of the boot at this level to a smaller size than the overall size of the flared end of binder 16. The difference in size however is so slight as to permit the flared end of the binder to be snapped past the bead 46 when the former has entered into full occupancy of the boot. Retaining collar 41 may then be slipped over the boot from its closed end and as the collar passes into engagement with the resilient boot arms 45 it cams them radially inward simultaneously until the extremities of arms 45 pass the first one of the shoulders 44. Here the arm extremity springs outward into conforming engagement with the conical counterbore 43. Thus the user has the choice of telescoping the collar 41 into the boot to a varying extent beyond that shown in Fig. 9. The collar can be forced a greater distance toward the open end of the boot so that the arms 45 engage any desired one of the conical counterbores 43 thus'increasing the overall length of the sheath as a whole. This is sometimes desirable when one or more of the insulated conductors have an unnecessary length of their wire or wires laid bare, needing a greater length of insulative protection by the collar 41. Fig. 11 shows in broken lines the positions to which the arms 45 spring inward to their relationship in the assemblage shown in Figs. 9 and 10 wherein the V-shaped notches have become nearly closed up.

As a guide to a successful relationship of wall thickness to other dimensions in a preferred embodiment of the invention, the tubular metallic binder if made of brass or copper and approximately .186 inch in minimum outside diameter may have a wall thickness of .015 inch. The boot 26 in Fig. '1 if made of molded nylon and approximately .265 inch in minimum inside diameter may have a wall thickness of .018 inch preferably thickened to .030 inch in the closed end of the boot. The wall thickness of boot 33 may be .025 inch but the prongs 34 are preferably thickened to .063 inch with hook terminals reduced to .032 inch in radial thickness. The retaining rings of molded nylon should have a circular wall thickness of at least .020 to .025 inch.

The foregoing are not limiting dimensions and as the principles underlying these improvements are susceptible of embodiment in many variations of the exact shapes and relationships of parts herein disclosed, the appended claims are directed to and intended to cover all equivalents which come within a broad interpretation of the terminology of the claims.

I claim:

1. A three-piece connector for binding together conductively and accessibly in an insulative enclosure a pig tail cluster of bared terminals of insulated electric wires comprising, a metallic splicer sleeve having a bell-shaped tubular Wall and containing the bared terminals of said insulated wires clinched together by indentations in a section of said bell-shaped wall having a relatively small girth, said wall section flaring outward to a relatively large girth as it extends along said wires in a direction away from said terminals and forming an open mouth of said sleeve, a thimble-shaped boot of resilient insulative material having a closed end and a bell-shaped tubular wall one portion of which wall adjacent said closed end of the boot telescopically encompasses and approximately conforms to said hell-shaped wall of said splicer sleeve and increases in girth as it extends along said wires in a direction away from said closed end of the boot and terminates in a ring of angularly spaced resilient prongs bordering said mouth of said splicer sleeve and projecting therebeyond, said prongs having barbed ends, and a cupshaped collar member having a rim wall of larger compass than said ring of prongs and a cross wall containing apertures positioned and shaped respectively to receive said barbed ends of said prongs and interlock therewith, said cross wall further having a central hollow lng projecting toward said splicer sleeve containing a single passageway therethrough suificiently large to pass all of said wires and of sufiiciently small external girth to enter and abut against said open mouth of said splicer sleeve.

2. A three-piece connector as defined in claim 1, in which the said barbed ends of the said resilient prongs occupy the interior of the said cup-shaped collar member.

3. A three-piece connector as defined in claim 1, in which there are more than two of the said resilient prongs angularly spaced about the said hollow lug.

4. A three-piece connector as defined in claim 1, in which the said resilient prongs are composed of nylon.

5. A three-piece connector as defined in claim 1, in which the said relatively large girth of the said splicer sleeve and the hollow lug of the said collar member telescopically overlap in a location to encompass the insulated electric wires.

References Cited in the file of this patent UNITED STATES PATENTS 1,626,875 Reiser May 3, 1927 2,589,368 Graham et al Mar. 18, 1952 2,665,353 Popp Jan. 5, 1954 2,701,273 Badeau Feb. 1, 1955 FOREIGN PATENTS 632,029 Great Britain Nov. 15, 1949